Turdnail Share definition Flag The kind of pinky toe nail that is too small to be called a nail. It is only a speck of nail that is just there. Toenail polish can't be painted on a turdnail because it's too small. Turdnail by Brenthutchinson1 June 9, 2015 0 0 Get merch Get the Turdnail mug. Buy Now — $32.95 See more merch